(JP)Infant rat heads grafted onto adults' thighs

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http://www.newscientist.com/news/news.jsp?id=ns99993135

 

Infant rat heads grafted onto adults' thighs

 

17:10 03 December 02

 

NewScientist.com news service

 

Infant rats are being decapitated and their heads

grafted onto the thighs of adults by researchers in

Japan.

 

If kept cool while the blood flow is stopped, a

transplanted brain can develop as normal for at least

three weeks, and the mouth of the head will move, as

if it is trying to drink milk, the team reports.

 

The grafted heads could be " excellent models " for

investigating brain function in human babies after

periods of no blood flow, known as ischemia, they

claim.

 

" Our main purpose is to investigate how the

transplanted brain can develop and maintain function

after prolonged total brain ischemia, " researcher

Nobufumi Kawai, at the Jichi Medical School in

Tochigi, told New Scientist. " And we tried to

investigate the effect of lowering the temperature of

the brain during the grafting. "

 

But other researchers are far from convinced by the

grisly technique. Denis Azzopardi of Imperial College

London, UK, who investigates brain injury in newborn

babies, says many well-characterised animal models of

studying brain ischemia already exist.

 

Public concern

 

" These are well established models for testing

different degrees of ischemia and potential

treatments. And there are plenty of studies showing

experimentally that cooling during ischemia can be

neuroprotective, " Azzopardi says. " So I'm not sure

that this complicated technique offers an advantage in

any way - I can't see it being widely used. "

 

Vivisection that provides no obvious research benefit

and involves clear animal suffering will only cause

public concern, adds a spokeswoman for the UK's

Research Defence Society, which advocates responsible

animal experimentation.

 

" Regulations in the UK are much stricter than in

Japan. If expert opinion says there are better or

other ways of doing an experiment that would cause

less animal suffering, it wouldn't be licensed, " she

told New Scientist.

 

Temperature sensitive

 

The Japanese team removed heads from 12-day-old rats

and waited 90 minutes before connecting them to the

blood supply in the thigh of an adult rat recipient.

" The grafted brain appeared to develop normally

provided the operation was done at the low temperature

of 19°C, " says Kawai. But in operations conducted at

29°C, still well below body temperature, the brain was

severely damaged.

 

In contrast, the standard animal models for studying

human infant ischemia involve, for example, tying the

carotid artery in rats. This halts blood flow to the

brain.

 

About one in 500 babies suffer from a lack of oxygen

during birth. This can happen if the placenta, which

supplies blood from the mother, becomes detached, or a

blockage forms. Azzopardi is part of a team

investigating whether cooling immediately after birth

can reduce subsequent brain damage.

 

Previous work, largely in animals, has shown that

cooling after brain injury reduces damage by

suppressing inflammation, for example.

 

Early results from the Japanese research are published

in Neuroscience Letters (vol 325, p 37).

 

Emma Young

 

 

 

 

 

 

 

 

 

 

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[Guest guest]

horrible...

 

>Early results from the Japanese research are published

>in Neuroscience Letters (vol 325, p 37).

 

www.sciencedirect.com/science?_ob=ArticleURL & _udi=B6T0G-45CDM19-5 & _user=10 & _cove\

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C000050221 & _version=1 & _urlVersion=0 & _userid=10 & md5=8480efb4da348797d73249c6c03cd\

1e0#aff1

 

 

Neuroscience Letters

Volume 325, Issue 1, 31 May 2002, Pages 37-41

 

DOI: 10.1016/S0304-3940(02)00213-6

PII: S0304-3940(02)00213-6

Copyright c 2002 Elsevier Science Ireland Ltd. All rights reserved.

 

Heterotopic graft of infant rat brain as an ischemic model for prolonged

whole-brain ischemia

 

Atsushi Niu, , a, Kuniko Shimazakib, Yasushi Sugawaraa, Toshiyuki Mizuib

and Nobufumi

Kawaib

 

a Department of Surgery, Jichi Medical School, Tochigi, Japan

b Department of Physiology, Jichi Medical School, Tochigi, Japan

 

Received 31 January 2002; revised 15 February 2002; accepted 19 February

2002. Available online 17 March 2002.

 

 

Abstract

 

By using a heterotopic brain graft model, we have made histological and

electrophysiological

studies of the infant rat brain after prolonged ischemia. An infant rat

head which had

undergone ischemia for more than 90 min, was grafted onto an adult rat by

anastomosing

the thoracic vessels to the femoral vessels of the host rat. Histological

and histochemical

studies carried out 10 days after the operation showed that the development

of the

hippocampus and cerebellum in the grafted brain appeared to be normal.

Interneuron growth

in the hippocampus and migration of the granule cells in the cerebellum had

occurred to a

similar extent as in control rats. Extracellular recordings in the

hippocampus showed normal

characteristics of the postsynaptic potentials including long-term

potentiation. This

heterotopic graft model would be useful for studying brain function after

long periods of

ischemia.

 

Author Keywords: Brain graft; Ischemia; Hippocampus; CA1; Cerebellum;

Development;

Infant; Rat

 

 

Corresponding author. Present address: Yaizu City Hospital, Dobara 1000,

Yaizu 425-8505,

Japan. Tel.: +81-54-623-3111; fax: +81-54-623-5146; email: niu

 

 

Neuroscience Letters

Volume 325, Issue 1, 31 May 2002, Pages 37-41